Greater London · England
New Build Mastic in New Eltham
New build mastic across New Eltham and nearby, with every bit of old sealant taken out first and a 12-month guarantee.
- Cracks appearing as a new home settles
- Skirting joints opening in the first winter
- Frame joints opening as the plaster dries
What affects the cost of new build mastic
Some jobs are bigger than they look, and some smaller. The main factors:
- The old material and how stubborn it is
- Any working-time requirements on site
- Which sealant suits the joint
- Whether the work is at height
Leaving a failed joint generally makes the job bigger, not smaller. If you’re not sure whether it needs doing, ring 0345 464 0079 or send us an email and we’ll give you an honest view and a quote.
What to tell us for a quote
Before you ask for a quote, have a think about:
- If it’s domestic, commercial or a hotel
- Photos by email, if that is easy
- Where the job is, and your postcode
- Any access issues, like height or stairs
To get a quote, ring 0345 464 0079 or email us with the location and a short description of the problem. We will send you a clear quote before any work starts.
About our new build mastic in New Eltham
Across New Eltham, we work for both new-home owners and the builders handing those homes over. One shower or a whole phase of plots, the method doesn’t change: remove, clean, prime where needed, then a neat new bead. We work on skirting & floors, bathrooms & en suites and windows & doors, and people most often call us about gaps between new skirting and floors and sealant work across a run of new homes.
London homes range from new-build flats to period conversions with new floors laid over old boards. Every joint between floor, skirting and threshold has to cope with some movement.
Big or small, you get the same 12-month guarantee in New Eltham and across Greater London.
- Where
- New Eltham (SE9, DA15, BR7)
- Wider area
- Greater London
- Cover
- A year, on every job
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Leave it or put it right?
A failed shower or bath seal in a new home lets water into floors and walls that are still drying out. Dealing with it early keeps the damage away from ceilings, floors and finishes. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. We take all of that into account in your quote.
Why us?
- Over 20 years’ experience
- Sanitary silicone with an anti-fungal additive in wet areas
- We never seal over old sealant
- Approved under the ARBOMaster scheme
New homes and floors in New Eltham
The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Much of London’s new housing is flats in larger developments, where snagging may go through the developer or managing agent.
As a London address, New Eltham can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. If you’ve bought a new home near New Eltham station, the sealant around baths, showers and frames is worth checking in the first year or two.
New Eltham is about 1 mile south-east of Eltham, in Greater London. Our applicators cover new build mastic for homes and businesses in New Eltham and nearby, as part of our work across Greater London. New Eltham is one of 764 towns and villages in Greater London where we work. We also work in London, around 8 miles away.
Work in SE9, DA15 and BR7 is quoted and booked the same way as anywhere else. If you need new build mastic at a property on Green Lane, Gerda Road and Novar Road or anywhere close by, our applicators can take on the job. If you are just outside New Eltham, we cover Eltham (1 mile north-west), Longlands (1 mile south-east), Coldharbour (1 mile south-west), Avery Hill (1 mile north) and Blackfen (1 mile north-east). Larger places within reach include London (8 miles north-west), City of Westminster (11 miles north-west), Marylebone (11 miles north-west), Kensington (13 miles west), St Pancras (10 miles north-west) and Shoreditch (9 miles north-west).
Landmarks near New Eltham
We work in homes and buildings around Elmstead Wood and St Thomas More Catholic Comprehensive School. New Eltham has its own railway station: New Eltham station. A little further out are Metropolitan Police Museum (1.4 miles east) and Eltham Community Hospital (1.1 miles north-west). Green spaces nearby include Summer Hill and The Tarn.
Nearby places to New Eltham
What else we do in New Eltham
What we do, step by step
We keep the work tidy and contained to the joints we’re treating. The job generally takes anything from a few hours to several days, depending on the number of plots, and we tell you how long to leave it before we go. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- We look at why each joint failed, including any movement.
- We remove the failed sealant and clean the joints.
- We make sure the joints are dry and prime them if needed.
- Baths are filled with water, then the new sealant is applied.
- We check every joint and leave you with the cure times.
Before we arrive
- Let us know about earlier repairs to the joints
- For indoor joints, keep the area dry beforehand if you can
- Mention any parking rules near the property
How to get a quote
Need a quote? Please phone 0345 464 0079 or drop us an email with a few details. You’ll know what we plan to do, and what it will cost, before any work begins.
Advice
Your questions about new build mastic in New Eltham
Is parking an issue for new build mastic in New Eltham?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Is New Eltham in your area for new build mastic?
Yes, New Eltham is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or drop us an email with a few details of the job.
Do you do commercial work?
Yes. Hotels, offices and other businesses use us and we’re fully insured.
Are you ARBOMaster approved?
Yes. We hold ARBOMaster approved applicator status, and we’re fully insured.
Where do you work from?
Mr Mastic is based in Crawley. We cover New Eltham and the rest of Greater London, along with the rest of our area.
Do you work through snagging lists?
Yes. Send us the sealant items on the list, with pictures if you can. We’ll flag anything that needs another trade.
Will the old sealant be removed?
Yes. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
Will there be a smell?
There can be a smell while the sealant cures. Opening a window helps.
What the job involves on each surface
Skirting and floors
As timber and screed dry, skirting and floors shift. Caulk cracks; a flexible sealant moves with it in a colour to suit.
Bathrooms and en suites
Trays and baths in new builds settle as they’re used. The joint is stripped back before the new bead goes in and baths are filled before sealing.
Work for landlords, hotels and businesses
From a single let to a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a one-year guarantee.
If you manage several properties in or around New Eltham, jobs at different addresses can be quoted together. Send us the addresses and the work at each, and pictures by email help.
DIY versus a professional finish
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is.
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Looking after it afterwards
After the cure time, these simple habits help:
- Watch for new gaps as the house dries out
- Get a leaking seal dealt with straight away
- Photograph failed sealant before it’s redone
- Avoid scourers and strong chemicals on sealant
Do not stand on the bath edge or the lip of the tray. Report any movement in a bath or tray.
The sooner you deal with untidy or cracking sealant, the less there is to put right. Left alone, a small crack can become a leak over time.